Safety cabinets have an operation chamber which is in a semi-sealed state except for its operation opening, and are configured to suck in contaminated aerosols which are generated in the operation chamber, and prevent the aerosols from flowing into an operator's side. They are also provided with a function of sterilizing and cleaning, by a HEPA filter, contaminated air which has been sucked in and collected, and then discharging the sterilized and cleaned air. They are classified into classes I, II, and III according to a level of pathogenic organs to be treated.
An example of such safety cabinets is known, as described in Patent Literature 1. With such conventional safety cabinets, for example, as shown in FIG. 4 and FIG. 5, an operation chamber 2 is provided above a workbench 1, and has an operation opening 3 in its front lower part, and the operation opening 3 is openable and closable by a shutter 4.
A slit-shaped inlet port 5 is provided along the front edge and the rear edge of the workbench 1. Air sucked in through the inlet port 5 circulates an air passage 7 due to the operation of a fan 6. A portion of the air is cleaned by an air cleaning units 8, such as a HEPA filter, and is again supplied into the operation chamber 2. The remaining portion of the air is cleaned by an air cleaning units 9, such as a HEPA filter, and is discharged outside through an exhaust port 17. In FIG. 4, the arrow shows the flow of air (airflow).
With such safety cabinet K, through a balance between an inflow airflow supplied into the operation chamber 2, a circulating airflow which is sucked in through the inlet port 5 provided at the front edge and the rear edge of the operation chamber 2, and circulates the air passage 7, and an airflow discharged outside, an air barrier B is formed at the operation opening 3, and the sterile environment and containment of the air in the operation chamber 2 is maintained.
While cell processing organisms, such as skin, cartilage, and a cornea, used for regenerative medicine are transplanted to a patient, in order to prevent exogenous microbial contamination, it is necessary to carry out this cell processing by an aseptic manipulation in an important zone, that is, a space which has a cleanliness of grade A.
On the other hand, since cell processing organisms from autogenous cells to be treated (hereinafter referred to as cells) are not necessarily sterile, an important zone, for example, the operation chamber 2 of the safety cabinet K may be contaminated due to aerosols which are generated by a processing operation. Because of this, in cases where the cell processing operation is carried out in the same equipment (safety cabinet K), decontamination and disinfection operations are carried out according to changeover procedures defined beforehand, and thus cross contamination is prevented.
The changeover means that after a processing process using cell tissue of a patient is completed, another process using cell tissue of another patient employed.
The changeover procedures are steps of decontaminating and disinfecting the surface to which aerosols and droplets may have adhered at the time of the cell processing operation for a patient. Environment of a workbench and the like in a room or in a safety cabinet, apparatuses such as a cultivation container and a pipette which directly contact cells, an operator's glove and the like, are decontaminated and disinfected according to a series of steps.
In an exchange operation of culture solution for which a conventional safety cabinet K is used, as shown in FIG. 5, in order to prevent cross contamination, a cultivation-container-storage-case 10 is opened outside of the safety cabinet K, a cultivation container 11 is taken out of the cultivation-container-storage-case 10, and the lid of the cultivation container 11 is opened in the operation chamber 2 of the safety cabinet K, and the culture solution is exchanged.
After the exchange operation of culture solution, in order to operate another patient's cell, it is necessary to decontaminate and disinfect the whole workbench 1 of the safety cabinet K according to the changeover procedures, and to prevent the cross contamination between the cells.